“Dirty Secrets of Flying:” What flight attendants and pilots admit about flying. For instance, always spread a cloth on your tray. Baby diapers have been changed there, and they haven’t been cleaned since. Bring an unopened box of chocolates for the crew and you’ll be treated extra special for the whole flight. Tip a flight attendant a fiver and you’ll likely get free drinks the rest of the flight. (No one thinks to tip.) And by the way, either the pilot or the co-pilot is usually asleep.